At first glance these two seems unrelated. Anthropology is the study of man. Writing is…well…a reflection of life. I don't care if you write fantasy or non-fiction, its life. There must be some sort of cultural common ground between the characters and the reader in order for the reader to "get it."
Knowing that the Zlpork wants his slitch means little to us. But if we learn that Zlpork is the hero and slitch is his soulmate, then we can relate to it. Suddenly, we want Zlpork to find his slitch and live happily ever after.
I once referred to the anthropologist's job as holding a mirror up to life and interpreting the reflection for those who can't see it for themselves.
That's the same thing writers do. We look at life, even when it only occurs in our heads, and we tell the people who don't share our mind what's going on. We show off the reflection of our creation.
Why not show off the creation itself? I firmly believe that no piece of writing will be exactly how the author sees it in his or her head. Even if it's as true as true can get and no detail is missed, the reader still interprets it and filters it through their own perspective. Thus, what the reader sees is the mirrors reflection not the object itself.
At least that's how I see it.